Does a specific muscle ache down there or all of them in the area? How deep is the pain? Right on the surface? Can you feel your tailbone move? Any grinding feeling?
Sounds like you just pulled a muscle, really. But then again I've never fully broken a bone before down there so I can't really say it is or isn't busted. I can relate to some of the pain though...
I recall one time I lost a bet with a friend and the condition of the loss was that she could kick me in the ass. I couldn't sit for a week, could barely walk, and going to the bathroom was damn near excruciating.
I guess that's what I get for making such a bet with a soccer player!